<template>
  <div class="todo-footer">
        <label>
          <input v-model="checkAll" type="checkbox" />
        </label>
        <span> <span>已完成{{ complateNum }}</span> / 全部{{ todoList.length }} </span>
        <button class="btn btn-danger" @click = "emit('clearComplate')">清除已完成任务</button>
      </div>
</template>

<script lang="ts">
 import { defineComponent } from 'vue'
  export default  defineComponent({
    name:'Footer'
  })
</script>
<script lang="ts" setup>
import{computed} from "vue"
import type { todoListType } from "../../App";

const emit = defineEmits<{
  (event: "allChecked", checkType: boolean): void;
  (event: "clearComplate"): void;
}>();

const props = defineProps<{ todoList: todoListType;}>()

//计算属性计算当前已经完成的数量
const complateNum = computed(() => {
  return props.todoList.reduce((p, c) => (c.done ? p + 1 : p), 0);
});

//全选按钮的可读可写的计算属性
const checkAll = computed({
  get() {
    return complateNum.value === props.todoList.length;
  },
  set(checkType) {
    emit("allChecked", checkType);
  },
});
  
</script>

<style lang="scss" scoped>
   /*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>